Rotatable tub construction for washing machines



April 23, 1957 R, SMITH 2,789,698

ROTATABLE TUB CONSTRUCTION FOR WASHING MACHINES INVENTOR.

AGENT T. R. SMITH April 23, 1957 ROTATABLE TUB CONSTRUCTION FOR WASHING MACHINES 4 Sheets-Sheet 2 Filed Jan. 9, 1955 Fla. 4

INVENTOR.

yomad l@ 5mi/ April 23, 1957 ROTATABLE TUB CONSTRUCTION FOR WASHING MACHINES Filed Jan. 9, 1953 T. R. SMITH 4 Sheets-Sheet 3 58 I )6 i |9 lO 65 'T I3 64 7 A 2 62-- g 0 0 0 O O O O 0 /34 eo` 0 o o O O 0 0 3s lw o o o o o o o o o o g 0 o o O O 0 0 n o o o o o o o o o l 5 o o o o o o o o 6 u o o o o .o o o o o 29` 0 0 o o O O O 0 Dn o o o o O O O 0 0 32" o o o o 45o A O o 0 o o o o o o @3J 0 0 4g o 33 3559. HI ,4 Fm 5 53 54 INVENTORL AGENT T. R. SMITH 2,789,698

ROTATABLE TUB CONSTRUCTION FOR WASHING MACHINES April 23, 1957 Filed Jan. 9, 195s 4 Sheets-Sheet 4 Fla. lO

JNVENTOR. 7m m AGENT RGTATABLE TUB CONSTRUCTION FOR WASHING MACHINES v Thomas R. Smith, Newton, Iowa, assigner to The Maytag Company, Newton, Iowa, a corporation of Delaware Application January 9, 1953, Serial No.330,446

8 Claims. (Cl. 21B-382) The invention relates to rotatable receptacles or tubs and more particularly to rotatable tubs for washing machines or the like which are rotated about their vertical axis.

This application is an improvement upon and is a continuation in part of my application Serial No.` 295,680, tiled lune 26, 1952, and assigned to the assignee of the present invention (now Patent No. 2,683,535).

Among the objects of` the invention is to provide a washing machine with an improved tub construction which when rotated about its vertical axis provides a means for removing heavy particles of dirt and sedimentary material therefrom.

In washing machines having rotatable tubs wherein a washing operation and a centrifugal liquid extraction operation takes place there are times, when washing some fabrics, that heavy particles of dirt, sand and other sedimentary material will settle out of the fabrics being washed. These particles tend to collect in the bottom of the tub during the washing operation and when the tub is rotated to extract the washing liquid, a portion of the heavy dirt or foreign matter may be forced back` into some of the fabrics which, of course, cause the same to be spotted or soiled. Even installations wherein a space or sediment trap is provided for sedimentary material to settle out of contact with the fabrics being washed, the material is not always removed therefrom when the tub is rotated and it may accumulate therein until it eventually clogs the sediment trap. This is especially so in installations where the settling space is not readily accessible for manual cleaning.

This invention is primarily directed to the removal of heavy dirt or sedimentary material from a fabric receiving tub of a washing machine which is rotatable about its vertical axis. In the several embodiments a tub construction is provided with a substantially vertical cylindrical sidewall which also forms a side or part of a vertically extending liquid conducting passage or passages having substantially constant areas throughout their length. Adjacent the lower end of the passage or passages is a sediment collecting space or spaces that lie in the bottom of the tub below the normal washing zone. This sediment collecting zone is .in direct communication with the interior of the tub so that during the washing operation sand and other sedimentary material may gravitate thereto and settle.

The upper portion of the tub is imperforate or sealed above the normal liquid level in order to prevent the escape of liquid to the exterior of the tub and to insure that, when the tub is rotated during the extraction operation, all or substantially all o f the liquid within the receptacle will pass downwardly in the direction of the sediment zone, through this zone whereat it entrains the sedimentary material and then upwardly through the constant area channel or channels and be discharged therefrom at the upper edge into a suitable catch basin.

An important consideration is that the channel or channels should be relatively narrow torestrict the `ow of E ttite States Patent O water to a degree and upon acceleration of the tub the pressure of the liquid is increased and causes the liquid carrying the sedimentary material in suspension to move rapidly upwardly through the vertically extending channels for discharge. By sealing the upper end of the receptacle and properly proportioning the area of the channels the pressure and velocity of the liquid will remove a major portion of the sedimentary material from the bottom of the tub, and by providing the tub with substantially a vertical cylindrical sidewall, specialized and expensive tub constructions are avoided.

Accordingly, it is one of the objects of the invention to provide a rotatable tub construction with a substantially vertical sidewall which is closed at its upper end to force the liquid to the bottom of the tub and then upwardly through a channel of substantially uniform area to remove sedimentary material from the bottom of the tub.

It is another object of the invention to provide a wash-- ing machine with a rotatable double tub construction having an annular liquid conducting space therebetweenI sealed at its upper portion to direct the liquid downwardly, and a plurality of upwardly directed liquid conducting channels having a substantially uniform area throughout extending from the bottom of the tub for discharging the liquid and sedimentary material out of the tub.

It is still another object of the invention to provide a washing machine with a rotatable double tub construction having an annular liquid conducting means therebetween which is divided to provide an inner channel for directing the liquid downwardly and an outer channel of substantially uniform area throughout its length for directing the liquid and sedimentary material upwardly therethrough.

It is yet another object of the invention to provide a washing machine having a rotatable double tub construction including an inner tub having a perforate lower section and an imperforate outer tub with an annular skirt therebetween and sealed at its upper portion to the inner tub which directs the washing liquid passing through the inner tub downwardly and then upwardly on the opposite side of the skirt to entrain sedimentary material collected at the bottom of the tub.

It is yet another object of the invention to provide a washing machine with a rotatable double tub construction including inner and outer tubs with substantially vertical and parallel sidewalls having a space therebetween which is sealed at its upper end to prevent the upward escape of liquid, and with a plurality of vertical channels of substantially uniform cross-sectional area throughout their lengths for conducting the liquid and sedimentary material from the bottom of the tub upwardly therethrough for discharge at a point above the normal liquid level within the tub. l

Other objects, features, advantages and capabilities. are comprehended by the invention as will later appear and as are inherently possessed thereby.

Referring to the drawings:

Figure l is a partial vertical longitudinal sectional view of a rotatable double tub construction for a washing machine with the improved liquid and sediment conducting means incorporated therein;

Figure 2 is a partial horizontal sectional view of the improved double tub construction taken generally on the l on the line 4-4of Figure 3;

3 Figures 5 and 6 are views similar to Figures l and 2 showing a mcdied double tub construction;

Figures 7 and 8 are enlarged detail sectional views of the tub construction shown in Figures 5 and 6;

Figures 9 and 10 are enlarged detail views of a modified vane construction disposed in the annular space in adouble tub construction.

Referring -now more in detail to the drawings for a combined washing and centrifugal liquid extraction machine embodying a rotatable tub of double wall construction made in accordance with the present invention, there is shown in Figures l to 4a tubv assembly 10 which is adapted to be rotated about its vertical axis. This tub assembly generally comprises a cup-shaped outer imperforate tub or receptacle 11 having a substantially vertical cylindrical sidewall 12, terminating in an upper open end dening a top edge 13 disposed above the normal liquid level A desired therein for the washing operation, and a genenally horizontal bottom wall 14, and a spaced inner tub or container 16, having perforations 17 in its lower portion, secured within the receptacle in spaced relation to provide an annular liquid conducting space 18 therebetween. The portion of the container 16 projecting above the top edge 13 of `the receptacle 11 is imperforate and terminates in la top opening 19 of reduced diameter through which the washing liquid is admitted to the tub and the fabrics `to be washed are inserted or removed.

The lower portion of the substantially cylindrical sidewall 12 of 'the imperforate receptacle 11 merges wit-h the generally horizontal bottom wall 14 in a relatively large and smooth curve 21 for -a reason to be hereinafter described. In addition, the sidewall 12 is formed to provide the outer Wal-l 22 of a plurality of equally spaced outwardly pressed recessed areas or sections 23, six in the example shown, having substantially vertical and parallel endwalls 24 defining with the outer w-all 22 a .pair of .oppositely disposd corners 26. These sections 23 extend from the upper open end 13 of the sidewall to the bottom of the tub, at which point each recessed section 23 merges into a recessed portion or pocket 2'7 formed in the bottom wall 14 of the tub. These pockets are of such size as to provide a group of spaced settling pockets or chambers 28 into which the sand and other sedimentary material collects during the washing operation.

The inner tub or container 16 is open ended and includes a cylindrical sidewall 29 `and a at bottom wall 31 disposed in substantially parallel spaced relation with respect to the side and bottom walls 12 and 14, respectively, of the imperforate receptacle 11 tov provide the relatively narrow annular liquid conducting space 13 therebetween. The bottom wall 31 and the major portion of 4the sidewall 29 of the container below the upper edge 13 of the receptacle is perforate to permit the free circulation of washing liquid between the 'annular space 18 and the interior of the container during the washing operation and free ilow of washing liquid therethrough during the extraction operation. This relatively narrow annular space includes an upper or vertical liquid con ducting space or section 32 between the sidewalls 12 and 29 and a lower radially extending horizontal annular liquid conducting space or section 33 between the bottom walls 14 and 31. In addition, the openings 17 in the bottom and side walls of the container readily permit the particles of sand and other sedimentary material to llow therethrough into the annular space and settle in the pockets 28 in the horizontal section during the washing operation. Therefore, in effect this space defines `a sediment collecting zone or space which functions in a maner -to be hereinafter described.

vThe inner tub or container 16 is rigidly secured in spaced relation to the receptacle 11 yto form a unitary structure in any suitable manner, such as, for` example,

by a suitable number of spacers or grommets 34 and.

screws or bolts 36, disposed adjacent the upper end of the receptacle, and the lower portion of the container is centered and held against radial displacement by providing a downwardly directed channel section 37 at the inner edge of the bottom wall 31 with an Iannullar U- shaped gasket 38, which in turn engages a vertical cylindrical shoulder 39 provided on the bottom wall 14 of the imperfor-ate receptacle. The upper portion 41 of the container extending above the itop 13 of the receptacle is preferably imperfonate and extends upwardly and inwardly to retain the fabrics being washed and to prevent Ithe discharge of washing liquid thereover during the centrifuging operation, and the upper end terminates to define the reduced opening 19 whereby the operator may gain access to the interior of the container.

Within the vertical annular space 32 between the sidewalls 12 and 29 and at each recessed section 23, there is provided a vertical resilient baille or partition member 42 extending from the upper edge 13 to adjacent the lower curved portion 21 of the sidewall 12 which cooperates with the recessed section to define a vertically extending relatively narrow channel 43 of substantially uniform cross-sectional area throughout its entire length. The sides 44 of each baille are bent outwardly as shown in Figures 2 and 4 and contact in the corners 26 provided by the, vertical endwalls 24 over their entire lengths to define the. arcuate length of each channel, and a plurality of inwardly extending projections or bosses 46 engage the outer periphery of the cylindrical wall of the conrainer to frictionally maintain the partition members 42 secured in position.

The vertical annular space 32 between the receptacle and container is sealed adjacent the upper end 13 of the receptacle by suitable sealing means, such as, for example, by an annular resilient element 47 formed from rubber or the like, which is pressed into the upper open end of the annular space to engage the receptacle 11, container 16 and upper innerA end of the bale 42. Thus 'the discharge of liquid upwardly through this space is prevented; however, the upper open ends of the vertical channels 43 remain open and unobstructed.

Washing means, such as, for example, a centrally located vertically mounted oscillatable agitator i3 is disposed within the confines of the container 14 to affect the proper washing action. This agitator may be oscillated by means of a shaft 49 whose lower end is connected to oscillating mechanism, generally referred to at 51, which in turn is operated by an inner shaft S2 driven atits lower end in any suitable manner by means of a drive motor (notrshown). The inner end of the horigontallwall 14 ofthe imperforate receptacle overlaps and 1s secured to the `outer peripheral portion S3 of a central hub 54 which journals the oscillatable shaft 49 and houses a portion of the oscillating mechanism. The hub 54 in turn is bolted to a gear 'housing 55 having a lower central tubular portion 56 rigidly secured to an outer vertical tubular shaft means 57 for supporting and rotating the entire tub assembly during the extraction operation. The inner shaft 52 for operating the oscillating mechanism 51 and the surrounding Vtubular shaft 57 extend downwardly and are supported by a combined radial and thrust bearing (not shown), and when the tub is rotated durins7 the liquid extraction operation the inner and outer shafts 52 and 57 are clutched o-r locked together in any suitable manner to rotate in unison.

While the particular mounting means for the rotatable tubr construction 1i) may be of any construction, in this instance the tub is intended to be mounted for lateral movement and a balancing ring 58 secured adjacent the upper open end 17 of the perforate container 13 is utilized to aid inV `balancing improperly distributed fabric loads during the extraction operation. Suitable additional mechanism `may be provided to either holld the tub stationary and` vertical .during the. washing operation or to aid in smoother operation when the tub is ,rotated during the extraction operation. i

It has been found that during the washing operation a major portion of the sedimentary material removed from the fabrics passes through the openings 17 in the container 16 and has a tendency to collect in the lower horizontal annular space 33 between bottom walls 14 and 31 of the perforate container and the receptacle. Under certain conditions, with a large majority of previous tub construction, it is rather difficult and in some instances impossible to remove this material should it be given time to settle therein. This being primarily due to the inherent design of the washing machine tubs, whether of single or double tub construction. Also, hereto-fore it has been assumed necessary, in order to remove the washing liquid from a rotatable tube, that the sidewall of the tub be tapered in the direction of the liquid exit or discharge point. This includes either a top or a bottom discharge tub construction.

With the above in mind it creates a considerable problem to remove sedimentary material, because if the tub is ared downwardly for bottom discharge the sloping passages formed in or in conjunction with the tub through which the liquid is discharged centrifugally results in an upwardly directed diverging type discharge passage. It is obvious that the velocity of the liquid pas-sing through a diverging passage decreases and while this decreased velocity will have very little or no effect as to the removal of water or dirt in the colloidal state from the tub, it does have a very marked elfect on the removal of sedimentary material, such as sand or the like.

In still other construct-ions wherein means are provided in the bottom of the tub for collecting sedimentary material which is intended to be discharged upwardly through channels or passages or the like, the bulk of the water is discharged from the tub through openings disposed above the normal liquid level. In such cases the major portion of the water is removed from the tub before the pressure of the liquid developed by the rotation of the tub is suiciently high to obtain the proper velocity of liquid through the channels to entrain the sedimentary material at the bottom of the tub and carry it upwardly therethrough for discharge. This latter point is important because, if the velocity is not high enough or should the passage diverge with its resultant decrease in velocity as mentioned in the first example, centrifugal force acting on the sedimentary material will cause it to separate from the water and move to the outer wall whereat it will adhere. While subsequent operations may remove a small portion of the retained sedimentary material the tendency is for the material to buildup at the bottom of the tub and in the passages and eventually clog the same.

It has been found that by providing a tub construction in which substantially all of the liquid in the tub is directed to the bottom of the tub and through a bottom discharge opening that if certain conditions are complied with a substantially high percentage of the sedimentary material, in the neighborhood of seventy-five to eighty percent or better, may be removed from the tub at the end of a complete washing and rinsing operation or cycle.

By way of example, in the modification previously described there is disclosed a tub construction wherein the receptacle 11 is approximately 2li/2 inches in diameter and ll inches in depth and the tub is adapted to normally retain about 14 gallons of Water during the Washing and rinsing operations. In this instance, the channels 43 extending from adjacent the bottom of the receptacle to the top edge 13 are approximately 81/2 inches long, 1/4 inch deep and 4% inches wide. By spacing six of these channels about the sidewall 12 approximately 6% square inches of discharge area will be provided. It has been found that with a rate of acceleration equal to about 1.6 radians per second squared that the optimum removal of heavy sand and other sedimentary material is approached. If the pluralityof channels are not utilized and an annular discharge area is utilized, as will be described in a later modification, it has been found an annular channel of the same length of 81/2 inches and 5%@ inch in width provides a satisfactory discharge area. In this case, the total discharge area approaches 12 square inches. While the removal of heavy sand is not quite as good in a tub using this larger discharge area, it still provides an effective means for the removal of the heavy dirt and sand.

It is to be understood the above dimensions are merely given by way of example and that the total desired discharge area may vary somewhat with other size tubs and conditions. However, it is believed that generally the smaller the total discharge area of the channels the more elective is the removal of the sedimentary material and sand from the bottom of the tub. This reduction in area, |however, must be modilied to a degree in order to obtain yoverall stability during the acceleration of the tub to high speeds.

As previously described the channels 43 have their lower open ends disposed adjacent the bottom of the tub and their upper open ends above the normal liquid level desired therein. These channels are restricted in total area and are of substantially uniform cross-section throughout their lengths so that the velocity of the liquid through the same is not reduced when the tub is rotated. By restricting the discharge area the initial rate of discharge of the washing liquid from the receptacle is reduced. As the speed of rotation increases the pressure or head of the water within the tub is increased, consequently the pressure drop across the channels 43 increases. This increased pressure drop increases the velocity of the liquid owing through the channels and since substantially all of the liquid must pass through or across the sediment zone or pockets 28 in passing to the inlets of the channels, the sand and other sedimentary material is entrained and passes upwardly with the water.

By suitably restricting these passages or channels so that the pressure drop is large, the velocity of the liquid passing axially therethrough will be high enough to overcome the tendency of centrifugal force acting radially on the sand and other sedimentary material to separate it from the liquid and move it toward and hold the same against the outer wall 22 of the channel 43. Even though some of the sand does contact the outer wall of the channel the velocity of the liquid will be such that a scouring action takes place along the walls to keep the dirt moving upwardly therealong.

While other means may be provided, it has been found a tub with a substantially vertical cylindrical sidewall will remove a suliicient quantity of washing liquid and that substantially vertically directed channels of substantially uniform area throughout their lengths are effective in the removal of liquid, and by restricting these passages so that the bulk of the water is retained within the tub until the same reaches R. P. M. a very high percentage of sand and other sedimentary material is removed from the bottom of the tub out of contact with the fabrics being Washed. It has also been found that with the particular tub construction shown the bulk of the sand and other sedimentary material remains in the tub until its rotation approaches l0() R. P. M. and between 100 and 200 R. P. M. the major portion of the sedimentary material is removed from the tub by the liquid owing through the channels.

It is to be understood that the above described tub construction may be modified as far as the particular details are concerned in several different ways and still embody the spirit of the invention.

From the foregoing it can be seen that when the tub 10 is stationary during the washing operation, the liquid and fabrics within the perforate container 16 are agitated rather violently by the vanes on the agitator 48 and due to this action a portion of the liquid is caused to continuously circulate through the openings 17 in the container into and out of the annular space 1S provided between the container and imperforate receptacle 11. VIn so doing a relatively large proportion of the heavy particles of sand and other sedimentary material removed from the fabrics will tend to pass through the openings into the annular space. Since the openings tend to break up the violent water action in the space, the sedimentary material will tend to :settle in the pockets 28 provided inthe horizontal botto-m wall 14.

After the washing operation, the tub is rotated about its vertical axis through the shaft means S2 and 57 to centrifugally extract the liquid therefrom. As the tub is accelerated, the washing liquid tends to move outwardly by centrifugal action and up the vertically extending channels 43 which aid in the acceleration of the rotation of the liquid about `the vertical axis. As the speed of rotation increases, the pressure of the liquid is ylikewise increased, thus the pressure drop across the channels increases accordingly which naturally results in an increase in the velocity of the liquid owing therethrough. By restricting the total discharge area of the channels 43, as previously mentioned, and providing an imperforate upper portion 41 on the container 16 the major portion of the liquid is retained in the tub. Also, since the annular space 18 is sealed at its upper end by the ring 47, all of the liquid must pass downwardly toward the lower open ends of the channels.

ln view of the fact the pressure of the liquid is proportional to the radius times the velocity squared and the imperforate upper portion of the container increases the head of the liquid, it can be seen that the velocity of the liquid moving through the channels is increased considerably as the tub -accelerates to higher speeds. As the tubs rotation is increased centrifugal force acting on the sedimentary material in the pockets 23 tends to move it radially outwardly in the direction of the outer wall and with the liquid moving radially over this horizontal section the sedimentary material is entrained therewith and is carried to the inlet of the channels 43. Due to the substantially uniform cross section' of the channels throughout their lengths and the high velocity of the liquid moving through the same lany tendency for the heavy dirt or sand to separate due to centrifugal force and lodge on the outer wall of the channel is retarded. Although a portion of the sand may contact the outer wall of the channel, the velocity of the liquid is high enough to provide a scouring action to keep the heavy material moving toward the upper open end. As the liquid and sedimentary material reaches the upper open end of the channels 43 it is discharged over the top t3 of the receptacle into a suitable catch basin (not shown).

Referring now to Figures 5 to 8 there is shown a slightly modified tub construction in which the plurality of channels have -been eliminated. In this instance, the imperforate outer tub or receptacle lll and inner tub or container 16 is of substantially the same construction as the rst mentioned modification; however, the recessed portions or pockets in the bottom wall of the receptacle have been eliminated. Since like parts are given like reference characters a further detailed description of these elements is not deemed necessary. The vertical portion of the annular space 32 between the sidewall 12 of the receptacle 11 and the sidewall 29 of the container i6 is divided by an annular skirt or cylindrical partition member 60 into inner and outer iluid conducting channels or passages 6 and 62, respectively. This skirt may be secured in spaced relation to the receptacle and container by means of the securing means 34 and 36. The lower edge 63 of the skirt 6i) terminates adjacent the bottom wall of the tub at the upper terminus of the curved portion 2l of the receptacle, while the upper edge of the skirt has an inturned portion 64 carrying an annular gasket or sealing means 65 which contacts the outer periphery of the vertical wall 29 of the container above the normal liquid level in the tub to seal the upper end of the inner channel 61 against the flow of liquid in the upward direction. The outer channel 62 has a substantially uniform cross-sectional area throughout its length, and is lprovided with a plurality of equally spaced generally vertically 'extending baflles or partition members 66, twelve in the embodiment shown. These batiies may -be secured in position by welding or like at the kllange 67 to the inner periphery of the cylindrical wall y12 of the receptacle and the radially inwardly projecting ends 68 are adapted to engage the outer periphery of the annular skirt 60 to hold the same in the proper spaced relation and provide a plurality of channel sections. The lower portion of the baflies extend downwardly beyond the lower edge 63 of the skirt to minimize snaring of lint and the like and they are relieved at 69 to provide passage means therethrough to readily permit the liquid to move from one section to the other at lthis point in the event the tub is being rotated under unbalanced load conditions toward the end of the liquid extraction operation. The primary object of the bailes 60 is to aid in rotating the liquid about the vertical axis and lto prevent the natural tendency for the liquid to slip relative to the tub. In this manner the balles aid in increasing the velocitiy of the liquid and thereby help to increase the pressure drop across the annular channel.

ln operation this rotatable tub performs in the same manner as that previously described. However, apparently due to the increased discharge area, the percentage of sedimentary material removed, while still good, is not as high as in the rst embodiment. It is obvious that as the tub is rotated all of the liquid is directed to the inlet of the outer channel 62 and no liquid is discharged at the upper portion of the container and the liquid may enter the outer annular channel 62 about the entire annular inlet area.

Figures 9 and l() disclosed a modified baffle construction 7l which is adopted to be used on a tub construction identical to that disclosed in Figures 5 to 8. In this instance, the baille construction 71 is formed by providing a plurality of spaced, vertical and inwardly directed creases in the vertical side wall 12 of the receptacle to divide the outer channel 62 into a plurality of sections. The inner rounded edges 72 of each baille terminates short of the annular skirt 60 and do not seal off each section. Thus, while the bailes aid in rotating the liquid, they likewise permit a portion of the liquid to move from one adjacent section to the other. By providing this space at the inner ends 72 of the baffle means and rounding its lower portion 73 suiciently, the possibility of sharing lint at the baffles with the resultant danger of clogging the passage is reduced considerably. In operation this tub construction is identical with that previously described.

Thus it can be seen that an eifective means has been provided to remove the sedimentary material from the bottom of the tub out 0f contact with clothes and the tendency of these sediment collecting pockets or zones to become clogged is for all practical purposes eliminated by means of the high velocity of the liquid passing through the same at the end of eachwashing and rinsing operation.

It has been found that a tub construction of the type disclosed provides a very eiective means for removing sedimentary material. It is to be understood, however, otherA details for single tub constructions may be provided to accomplish the same result. This invention has in mind the features of a tub construction with substantially vertical sidewalls in which all or the bulk of the liquid passes toward the bottom of the tub whereat it entrains sedimentary material and then moves vertically upward-ly through a channel or channels having a substantially constant area throughoutl their entire lengths and in which the channels total area is restricted to ensure the proper velocity of liquid.

From the foregoing it can be seen that an improved rotatable tub construction for a washing machine has been provided which has a substantially vertical sidewall with a channel or channels of substantially uniform crosssectional area throughout their lengths disposed in association with the sidewall, and that the channels are so proportioned that the intial discharge of liquid is restricted in order to increase the velocity of the liquid to entrain the sedimentary material in the bottom of the tub and carry the same upwardly through the channels out of contact with clothes. In addition, the tub is so designed that substantially all of the washing liquid moves downwardly to the lower portion of the tub along the vertical sidewalls. Also, a double tub construction may be provided to improve the operation as to the water removal for a given speed of rotation.

While I have herein described and upon the drawings shown illustrative embodiments of the invention, it is to be understood that the invention is not limited thereto but may comprehend other constructions, arrangements of parts, details and features without departing from the spirit of the invention.

It is claimed:

1. A tub construction for a washing machine adapted to receive washing liquid and fabrics to be washed and rto be rotated about a vertical axis to extract the liquid therefrom, comprising an imperforate receptacle having a substantially vertical cylinrical sidewall with an upper open end and a bottom wall, a container having a perforate lower portion disposed in said receptacle in spaced relation thereto to define an annular channel therebetween and having an imperforate upper portion terminating in an opening of reduced diameter to restrict the ow of liquid thereover and for Iinsertion and removal of the fabrics, means for sealing the upper end of said annular channel, said receptacle having vertical extending recesses in its sidewall, and a partition member associated with each of said recesses to provide a plurality of vertically extending channels of substantially uniform cross-sectional area from the lower to the upper edge of said receptacle and through which substantially all of the liquid is discharged to ush accumulated sediment from the bottom of said receptacle upwardly through said vertically extending channels upon rotation of said tub.

2. The invention of claim 1, said imperforate receptacle being provided with sump pockets underlying said vertically extending channels and communicating therewith.

3. A rotatable tub assembly for a washing machine comprising, inner and outer walls spaced from each other, partition members between said walls, said outer Wall being imperforate and having vertical sectors cooperating with said partition members to dene spaced eluent ducts extending upwardly from the bottom of said tub assembly to the upper limits of said outer wall, said inner wall having perforations confronting said outer wall for the radial delivery of liquid from within said tub assembly outwardly through said inner wall and against said outer wall, said partition members shielding' said sectors from liquid passing through said inner wall to preclude the admission of liquid to said ducts except adjacent the bottom of the latter, so as to maintain an upward axial liquid tlow therethrough upon rotation of said tub assembly, and sealing means closing substantially the entire upper limits of the space between said inner and outer walls except the tops of said ducts.

4. The invention of claim 3, said outer wall including sectorial sumps underlying and communicating with said ducts.

5. A rotatable tub assembly for a washing machine, comprising, inner and outer walls spaced from each other, said outer wall being imperforate and provided with upstanding recesses about its periphery, partition members between said walls cooperating with said recesses to define euent ducts extending from the bottom of said tub assembly to the upper limits of said outer wall, said inner wall having perforations confronting said ou-ter wall for radial delivery of liquid from within said tub assembly outwardly through said inner wall and lagainst said outer wall, said partition members covering said recesses and precluding the admission of liquid to said ducts except adjacent the bottom of the latter, so as to maintain an upward axial liquid ow therethrough upon the rotation of said tub assembly, and sealing means closing substantially the entire upper limits of the space between said inner and outer walls except the tops of said ducts.

6. The invention of claim 5, said outer wall including sediment pockets underlying said ducts and directly communicating therewith.

7. A washing machine tub assembly adapted to receive liquid and to be rotated for extraction of liquid and sediment therefrom, comprising, a receptacle including imperforate side and bottom walls, a perforate inner wall within said receptacle spaced from said side and bottom walls, upstanding recesses formed in said side wall and extending throughout the height of said side wall, partition members bridging said recesses to form etlluent ducts communicating with the bottom of said ltub assembly, and sealing means closing substantially the entire limits of the space between said side wall and said inner wall except the tops of said ducts.

8. The invention of claim 7, said bottom wall being provided with sediment retaining sumps underlying and communicating with said effluent ducts.

References Cited in the tile of this patent UNITED STATES PATENTS Re. 23,626 Castner Mar.A 10, 1953 1,410,146 Von May Mar. 21, 1922 2,274,402 Dunham Feb. 24, 1942 2,375,635 Dyer May 8, 1945 2,384,784 Tholl Sept. 11, 1945 2,683,535 Smith July 13, 1954 

